Residential homes and commercial buildings are typically wired to provide electrical power via electrical outlets. Inspecting this wiring to identify faults may be time-consuming, expensive and/or impractical depending on the extent or layout of the wiring.
Existing diagnostic units may electrically connect a light source across the line to neutral, line to ground, and neutral to ground of a power distribution circuit. If properly wired, the light source turns on when connected across the line to neutral or line to ground. If improperly wired, the light source turns on when connected across the neutral to ground.